Requests模块

一、Content-Type

Content-Type，内容类型，一般是指网页中存在的Content-Type，用于定义网络文件的类型和网页的编码，决定浏览器将以什么形式、什么编码读取这个文件。Content-Type属性指定请求和响应的HTTP内容类型。如果未指定 ContentType，默认为text/html

二、常见的编码格式

application/x-www-form-urlencoded            格式 -->  a=1&b=2

application/json                                            格式 --> {"a":"2","b":"2"}

multipart/form-data

三、Requests模块

Requests是用python语言基于urllib编写的，采用的是Apache2 Licensed开源协议的HTTP库，Requests它会比urllib更加方便，可以节约我们大量的工作。一句话，requests是python实现的最简单易用的HTTP库，建议爬虫使用requests库。默认安装好python之后，是没有安装requests模块的，需要单独通过pip安装

四、安装

pip install requests

五、Requests.get

requests.get(url, params=None, **kwargs)

url : 网站地址

import  requests

url = "https://www.douban.com/"
# GET请求，会返回结果
response = requests.get(url)
# response.text查看结果
print(response.text)

params:参数

import requests

# 请求带参数的网页
response1 = requests.get('https://www.douban.com/search?q=新喜剧之王')
print(response1.text)

# 请求带参数的网页
response2 = requests.get('https://www.douban.com/search',params={"q":"新喜剧之王"})
print(response2.text)

headers:请求头

import requests

# 请求请求头
headers = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36"}
response = requests.get("https://www.baidu.com",headers=headers)
print(response.text)

cookies：带cookies的请求

import uuid
import requests

cookies = dict(token=str(uuid.uuid4()))
url = 'http://httpbin.org/cookies'
# 带cookies的请求
response = requests.get(url=url,cookies=cookies)
print(response.text)

'''
{
  "cookies": {
    "token": "5c4478cd-b987-4103-b224-92fab6cf7b22"
  }
}
'''

六、request.post

requests.post(url, data=None, json=None, **kwargs)

data是指application/x-www-form-urlencoded格式的数据

import requests

url = "http://httpbin.org/post"
# 发送application/x-www-form-urlencoded格式的数据，用data
response = requests.post(url,data={"a":1,"b":2})
print(response.text)

'''
{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {
    "a": "1", 
    "b": "2"
  }, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip, deflate", 
    "Connection": "close", 
    "Content-Length": "7", 
    "Content-Type": "application/x-www-form-urlencoded", 
    "Host": "httpbin.org", 
    "User-Agent": "python-requests/2.21.0"
  }, 
  "json": null, 
  "origin": "121.35.182.63", 
  "url": "http://httpbin.org/post"
}
'''

json是指application/json格式的数据

import requests

url = "http://httpbin.org/post"
# 发送application/json格式的数据，用json
response = requests.post(url,json={"a":1,"b":2})
print(response.text)

'''
{
  "args": {}, 
  "data": "{"a": 1, "b": 2}", 
  "files": {}, 
  "form": {}, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip, deflate", 
    "Connection": "close", 
    "Content-Length": "16", 
    "Content-Type": "application/json", 
    "Host": "httpbin.org", 
    "User-Agent": "python-requests/2.21.0"
  }, 
  "json": {
    "a": 1, 
    "b": 2
  }, 
  "origin": "121.35.182.63", 
  "url": "http://httpbin.org/post"
}
'''